THUMB FOR A BACKHOE

MACHOIRE POUR PELLE RETROCAVEUSE

English Abstract

A digging implement (10) including an extendable linkage (12) including a
bucket (14) and a thumb assembly (34) for holding materials in the bucket
(14). The thumb assembly (34) is configured to rotate as the linkage (12)
extends, and both the bucket (14) and the thumb assembly (34) are
independently operable.

French Abstract

L'invention concerne un outil de creusage (10) comprenant une articulation pouvant s'étendre (12) qui comprend une benne de chargement (14) et un ensemble de mâchoire (34) destiné à maintenir des matériaux dans ladite benne (14). L'ensemble de mâchoire (34) est conçu pour effectuer une rotation pendant que l'articulation s'étend, aussi bien la benne (14) que l'ensemble de mâchoire (34) pouvant être utilisé de façon indépendante.

Claims

The invention claimed is:
1. A digging implement comprising:
an extendable linkage including a bucket; and
a thumb assembly for holding materials in said bucket,
wherein said thumb assembly is configured to rotate as said linkage extends,
and
both said bucket and said thumb assembly are independently operable.
2. The digging implement as recited in claim 1, wherein:
said extendable linkage includes a first telescoping body and a second
telescoping
body, said linkage being configured to elongate as said first and second
telescoping
bodies telescope, said bucket being rotatably connected to the second
telescoping body.
3. The digging implement as recited in claim 2, wherein:
said thumb assembly includes:
a thumb rotatably connected to the second telescoping body; and
an arm rotatably connected to said first telescoping body and said thumb;
wherein said arm will force said thumb to rotate about said second telescoping
body as said first and second telescoping bodies telescope.
4. The digging implement as recited in claim 3, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
5. The digging implement as recited in claim 4, wherein:
said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
6. The digging implement as recited in claim 5, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said
arm and a third cross beam for gripping objects between said bucket and said
thumb.
-8-

7. The digging implement as recited in claim 6, wherein:
said U-shaped first cross beam includes a base extending between said pair of
parallel beams and a pair of legs extending outside of the pair of parallel
beams, one of
said legs being removably attached to said base for allowing said thumb to be
easily
attached to and removed from said linkage.
8. The digging implement as recited in claim 1, wherein:
said bucket and said thumb assembly are rotatably connected to an end of said
extendable linkage at a pivot point.
9. In a digging implement having a linkage including a first telescoping body
and a
second telescoping body, said linkage configured to elongate as said first and
second
telescoping bodies telescope, and a bucket rotatably connected to an end of
said second
telescoping body, the improvement comprising:
a thumb assembly rotatably connected to said end of said second telescoping
body
at a pivot point and to an end of said first telescoping body;
wherein said thumb assembly is forced about said pivot point as said first and
second telescoping bodies telescope, and both said bucket and said thumb
assembly are
independently operable.
10. The digging implement as recited in claim 9, wherein:
said thumb assembly includes:
a thumb rotatably connected to the second telescoping body; and
an arm rotatably connected to said first telescoping body and said thumb;
wherein said arm will force said thumb to rotate about said second telescoping
body as said first and second telescoping bodies telescope.
11. The digging implement as recited in claim 10, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
12. The digging implement as recited in claim 11, wherein:
-9-

said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
13. The digging implement as recited in claim 12, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said
arm and a third cross beam for gripping objects between said bucket and said
thumb.
14. The digging implement as recited in claim 13, wherein:
said U-shaped first cross beam includes a base extending between said pair of
parallel beams and a pair of legs extending outside of the pair of parallel
beams, one of
said legs being removably attached to said base for allowing said thumb to be
easily
attached to and removed from said linkage.
15. The digging implement as recited in claim 9, wherein:
said bucket is rotatably connected to said second telescoping body at said
pivot
point.
16. A digging implement comprising:
a linkage including a first telescoping body and a second telescoping body,
said
linkage configured to elongate as said first and second telescoping bodies
telescope;
a bucket connected to an end of said second telescoping body; and
a thumb assembly rotatably connected to said end of said second telescoping
body
at a pivot point and to an end of said first telescoping body;
wherein said thumb is forced about said pivot point as said first and second
telescoping bodies telescope, and both said bucket and said thumb are
independently
operable.
17. The digging implement as recited in claim 16, wherein:
said thumb assembly includes:
a thumb rotatably connected to the second telescoping body; and
an arm rotatably connected to said first telescoping body and said thumb;
-10-

wherein said arm will force said thumb to rotate about said second telescoping
body as said first and second telescoping bodies telescope.
18. The digging implement as recited in claim 17, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
19. The digging implement as recited in claim 18, wherein:
said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
20. The digging implement as recited in claim 17, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said
arm and a third cross beam for gripping objects between said bucket and said
thumb.
21. The digging implement as recited in claim 20, wherein:
said U-shaped first cross beam includes a base extending between said pair of
parallel beams and a pair of legs extending outside of the pair of parallel
beams, one of
said legs being removably attached to said base for allowing said thumb to be
easily
attached to and removed from said linkage.
22. The digging implement as recited in claim 16, wherein:
said bucket is rotatably connected to said second telescoping body at said
pivot
point.
23. A thumb assembly for connection for a digging implement having a linkage
including a first telescoping body and a second telescoping body, the linkage
configured
to elongate as the first and second telescoping bodies telescope, the digging
implement
also including a bucket connected to an end of the second telescoping body,
the thumb
assembly comprising:
a thumb configured for rotatable connection to the second telescoping body;
and
-11-

an arm configured for rotatable connection to the first telescoping body and
the
thumb;
wherein the arm will force said thumb, when both said arm and said thumb are
connected to the digging implement, to rotate about the second telescoping
body as the
first and second telescoping bodies telescope; and
wherein both the thumb and the bucket are independently operable when both
said arm and said thumb are connected to the digging implement.
24. The thumb assembly as recited in claim 23, wherein:
said thumb is configured to be rotatably connected to an end of the second
telescoping body, wherein said bucket and said thumb would have a common axis
of
rotation.
25. The thumb assembly as recited in claim 24, wherein:
said arm is configured to be rotatably connected to an end of said first
telescoping body and to a center portion of said thumb on a side of said thumb
opposite
said bucket.
26. The thumb assembly as recited in claim 23, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to the second telescoping body, a second cross beam for connection
to said
arm and a third cross beam for gripping objects between the bucket and said
thumb.
27. The thumb assembly as recited in claim 26, wherein:
said U-shaped first cross beam includes a base extending between said pair of
parallel beams and a pair of legs extending outside of the pair of parallel
beams, one of
said legs being removably attached to said base for allowing said thumb to be
easily
attached to and removed from said linkage.
28. The thumb assembly as recited in claim 23, further including:
a shoulder configured to attachment to the first telescoping body, said
shoulder
for rotatably connecting said arm to said first telescoping body.
-12-

29. A method of connecting a thumb assembly to a digging implement having a
linkage including a first telescoping body and a second telescoping body, the
linkage
configured to elongate as the first and second telescoping bodies telescope,
the digging
implement also including a bucket connected at a pivot point to an end of the
second
telescoping body, the method comprising:
rotatably connecting a thumb to said second telescoping body at the pivot
point;
and
rotatably connecting an arm to said first telescoping body and said thumb;
wherein the arm will force said thumb, when both said arm and said thumb are
connected to the digging, implement, to rotate about the second telescoping
body as the
first and second telescoping bodies telescope; and
wherein both the thumb and the bucket are independently operable when both
said arm and said thumb are connected to the digging implement.
-13-

CLAIMS
1. A digging implement comprising:
an extendable linkage including a bucket; and
a thumb assembly for holding materials in said bucket,
wherein said thumb assembly is configured to rotate as said linkage extends,
and
both said bucket and said thumb assembly are independently operable.
2. The digging implement as recited in claim 1, wherein:
said extendable linkage includes a fast telescoping body and a second
telescoping
body, said linkage being configured to elongate as said first and second
telescoping bodies
telescope, said bucket being rotatably connected to the second telescoping
body.
3. A digging implement comprising:
an extendable linkage including a bucket; and
a thumb assembly for holding materials in said bucket,
wherein said thumb assembly is configured to rotate as said linkage extends,
and
both said bucket and said thumb assembly are independently operable;
wherein said extendable linkage includes a first telescoping body and a second
telescoping body, said linkage being configured to elongate as said first and
second
telescoping bodies telescope, said bucket being rotatably connected to the
second
telescoping body;
wherein said thumb assembly includes a thumb rotatably connected to the second
telescoping body and an arm rotatably connected to said first telescoping body
and said
thumb; and
wherein said arm will force said thumb to rotate about said second telescoping
body
as said first and second telescoping bodies telescope.
4. The digging implement as recited in claim 3, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
14

5. The digging implement as recited in claim 4, wherein:
said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
6. The digging implement as recited in claim 5, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said arm
and a third cross beam for gripping objects between said bucket and said
thumb.
7. The digging implement as recited in claim 6, wherein:
said U shaped first cross beam includes a base extending between said pair of
parallel beams and a pair of legs extending outside of the pair of parallel
beams, one of said
legs being rernovably attached to said base for allowing said thumb to be
easily attached to
and removed from said linkage.
8. The digging implement as recited in claim 1, wherein:
said bucket and said thumb assembly are rotatably connected to an end of said
extendable linkage at a pivot point.
9, In a digging implement having a linkage including a first telescoping body
and a
second telescoping body, said linkage configured to elongate as said first and
second
telescoping bodies telescope, and a bucket rotatably connected to an end of
said second
telescoping body, the improvement comprising:
a thumb assembly rotatably connected to said end of said second telescoping
body at
a pivot point and to an end of said fast telescoping body;
wherein said thumb assembly is forced about said pivot point as said first and
second telescoping bodies telescope, and both said bucket and said thumb
assembly are
independently operable.
10.In a digging implement having a linkage including a first telescoping body
and a
second telescoping body, said linkage configured to elongate as said first and
second
telescoping bodies telescope, and a bucket rotatably connected to an end of
said second
telescoping body, the improvement comprising;
15

a thumb assembly rotatably connected to said end of said second telescoping
body at
a pivot point and to an end of said first telescoping body;
wherein said thumb assembly is forced about said pivot point as said first and
second telescoping bodies telescope, and both said bucket and said thumb
assembly are
independently operable;
wherein said thumb assembly includes a thumb rotatably connected to the second
telescoping body and an arm rotatably connected to said first telescoping body
and said
thumb; and
wherein said arm will force said thumb to rotate about said second telescoping
body
as said first and second telescoping bodies telescope.
11. The digging implement as recited in claim 10, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
12. The digging implement as recited in claim 11, wherein:
said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
13. The digging implement as recited in claim 12, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said arm
and a third cross beam for gripping objects between said bucket and said
thumb.
14. The digging implement as recited in claim 13, wherein:
said U-shaped first cross beam includes a base extending between said pair of
parallel beams and a pair of legs extending outside of the pair of parallel
beams, one of said
legs being removably attached to said base for allowing said thumb to be
easily attached to
and removed from said linkage.
15. The digging implement as recited in claim 9, wherein:
said bucket is rotatably connected to said second telescoping body at said
pivot
point.
16

16. A digging implement comprising:
a linkage including a first telescoping body and a second telescoping body,
said
linkage configured to elongate as said first and second telescoping bodies
telescope;
a bucket connected to an end of said second telescoping body; and
a thumb assembly rotatably connected to said end of said second telescoping
body at
a pivot point and to an end of said first telescoping body;
wherein said thumb assembly is forced about said pivot point as said first and
second telescoping bodies telescope, and both said bucket and said thumb
assembly are
independently operable.
17. A digging implement comprising:
a linkage including a first telescoping body and a second telescoping body,
said
linkage configured to elongate as said first and second telescoping bodies
telescope;
a bucket connected to an end of said second telescoping body; and
a thumb assembly rotatably connected to said end of said second telescoping
body at
a pivot point and to an end of said first telescoping body;
wherein said thumb is forced about said pivot point as said first and second
telescoping bodies telescope, and both said bucket and said thumb are
independently
operable;
wherein said thumb assembly includes a thumb rotatably connected to the second
telescoping body and an arm rotatably connected to said first telescoping body
and said
thumb; and
wherein said arm will force said thumb to rotate about said second telescoping
body
as said first and second telescoping bodies telescope.
18. The digging implement as recited in claim 17, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
19. The digging implement as recited in claim 18, wherein:
said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
17

30. A digging machine comprising:
a mobile base;
an extendable linkage connected at a first end to the mobile base and at a
second end
to a bucket; and
a thumb assembly for holding materials in said bucket,
wherein said thumb assembly is configured to rotate as said linkage extends,
and
both said bucket and said thumb assembly are independently operable.
31. The digging machine as recited in claim 30, wherein:
said extendable linkage includes a fast telescoping body and a second
telescoping
body, said linkage being configured to elongate as said first and second
telescoping bodies
telescope, said bucket being rotatably connected to the second telescoping
body.
32. The digging machine as recited in claim 30, wherein;
said bucket and said thumb assembly are rotatably connected to an end of said
extendable linkage at a pivot point.
33. In a digging machine having a mobile base and a linkage connected to the
mobile
base, the linkage including a first telescoping body connected to the mobile
base and a
second telescoping body, said linkage configured to elongate as said first and
second
telescoping bodies telescope, and a bucket rotatably connected to an end of
said second
telescoping body, the improvement comprising:
a thumb assembly rotatably connected to said end of said second telescoping
body at
a pivot point and to an end of said first telescoping body;
wherein said thumb assembly is forced about said pivot point as said first and
second telescoping bodies telescope, and both said bucket and said thumb
assembly are
independently operable.
34. The digging machine as recited in claim 33, wherein:
said thumb assembly includes:
a thumb ratatably connected to the second telescoping body; and
an arm rotatably connected to said first telescoping body and said thumb;
18

wherein said arm will force said thumb to rotate about said second telescoping
body
as said first and second telescoping bodies telescope.
35. The digging machine as recited in claim 33, wherein:
said bucket is rotatably connected to said second telescoping body at said
pivot
point.
36. A digging machine comprising:
a mobile base;
a linkage including a first telescoping body connected to the mobile base and
a
second telescoping body, said linkage configured to elongate as said first and
second
telescoping bodies telescope;
a bucket connected to an end of said second telescoping body; and
a thumb assembly rotatably connected to said end of said second telescoping
body at
a pivot point and to an end of said first telescoping body;
wherein said thumb assembly is forced about said pivot point as said first and
second telescoping bodies telescope, and both said bucket and said thumb
assembly are
independently operable.
37. The digging machine as recited in claim 36, wherein:
said thumb assembly includes:
a thumb rotatably connected to the second telescoping body; and
an arm rotatably connected to said first telescoping body and said thumb;
wherein said arm will force said thumb to rotate about said second telescoping
body
as said first and second telescoping bodies telescope.
38. The digging machine as recited in claim 37, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
19

39. The digging machine as recited in claim 37, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said arm
and a third cross beam for gripping objects between said bucket and said
thumb.
40. The digging machine as recited in claim 36, wherein:
said bucket is rotatably connected to said second telescoping body at said
pivot
point.
41. A digging implement comprising:
an extendable linkage including a bucket; and
a thumb assembly for holding materials in said bucket,
wherein said thumb assembly is configured to rotate as said linkage extends;
wherein both said bucket and said thumb assembly are independently operable;
and
wherein said thumb assembly is removably connected to said extendable linkage.
42. The digging implement as recited in claim 41, wherein:
said extendable linkage includes a first telescoping body and a second
telescoping
body, said linkage being configured to elongate as said first and second
telescoping bodies
telescope, said bucket being rotatably connected to the second telescoping
body.
43. The digging implement as recited in claim 42, wherein:
said thumb assembly includes:
a thumb rotatably connected to the second telescoping body; and
an arm rotatably connected to said first telescoping body and said thumb;
wherein said arm will force said thumb to rotate about said second telescoping
body
as said first and second telescoping bodies telescope.
44. The digging implement as recited in claim 43, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.

45. The digging implement as recited in claim 44, wherein:
said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
46. The digging implement as recited in claim 45, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said arm
and a third cross beam for gripping objects between said bucket and said
thumb.
47. The digging implement as recited in claim 41, wherein:
said bucket and said thumb assembly are rotatably connected to an end of said
extendable linkage at a pivot point.
48. The digging implement as recited in claim 41, wherein:
said bucket is removably connected to said extendable linkage with a pivot
pin; and
said pivot pin includes a removable collar for allowing said pivot pin to be
removed
from said bucket and said extendable linkage.
49. In a digging implement having a linkage including a first telescoping body
and a
second telescoping body, said linkage configured to elongate as said first and
second
telescoping bodies telescope, and a bucket rotatably connected to an end of
said second
telescoping body, the improvement comprising:
a thumb assembly rotatably connected to said end of said second telescoping
body at
a pivot point and to an end of said first telescoping body;
wherein said thumb assembly is forced about said pivot point as said first and
second telescoping bodies telescope, and both said bucket and said thumb
assembly are
independently operable; and
wherein said thumb assembly is removably connected to said second telescoping
body and to said first telescoping body.
50. The digging implement as recited in claim 49, wherein:
sand thumb assembly includes:
a thumb rotatably connected to the second telescoping body; and
21

an arm rotatably connected to said first telescoping body and said thumb;
wherein said arm will force said thumb to rotate about said second telescoping
body
as said first and second telescoping bodies telescope.
51. The digging implement as recited in claim 50, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
52. The digging implement as recited in claim 51, wherein:
said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
53. The digging implement as recited in claim 52, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said arm
and a third cross beam for gripping objects between said bucket and said
thumb.
54. The digging implement as recited in claim 49, wherein:
said bucket is rotatably connected to said second telescoping body at said
pivot
point.
55. The digging implement as recited in claim 49, wherein:
said bucket is removably connected to said second telescoping body with a
pivot
pin; and
said pivot pin includes a removable collar for allowing said pivot pin to be
removed
from said bucket and said second telescoping body.
56. A digging implement comprising:
a linkage including a first telescoping body and a second telescoping body,
said
linkage configured to elongate as said first and second telescoping bodies
telescope;
a bucket connected to an end of said second telescoping body; and
a thumb assembly rotatably connected to said end of said second telescoping
body at
a pivot point and to an end of said first telescoping body;
22

wherein said thumb assembly is forced about said pivot point as said first and
second telescoping bodies telescope, and both said bucket and said thumb
assembly are
independently operable; and
wherein said thumb assembly is removably connected to said second telescoping
body and to said first telescoping body.
57. The digging implement as recited in claim 56, wherein:
said thumb assembly includes:
a thumb rotatably connected to the second telescoping body; and
an arm rotatably connected to said first telescoping body and said thumb;
wherein said arm will force said thumb to rotate about said second telescoping
body
as said first and second telescoping bodies telescope.
58. The digging implement as recited in claim 57, wherein:
said bucket and said thumb are rotatably connected to an end of the second
telescoping body, said bucket and said thumb having a common axis of rotation.
59. The digging implement as recited in claim 58, wherein:
said arm is rotatably connected to an end of said first telescoping body and
to a
center portion of said thumb on a side of said thumb opposite said bucket.
60. The digging implement as recited in claim 57, wherein:
said thumb includes a pair of parallel beams with a U-shaped first cross beam
for
connection to said second telescoping body, a second cross beam for connection
to said arm
and a third cross beam for gripping objects between said bucket and said
thumb.
61. The digging implement as recited in claim 56, wherein:
said bucket is rotatably connected to said second telescoping body at said
pivot
point.
23

Description

CA 02400917 2002-08-29
WO 02/10522 PCT/US00/20687
THUMB FOR A BACKHOE
BACKGROUND OF THE INVENTION
A. Field of the Invention
The present invention relates to digging implements, and in particular a
backhoe.
B. Background of the Art
Backhoes are used extensively for excavating and for carrying objects from one
area to another. Backhoes have typically been used to dig holes in the ground
for
trenches and for the placement of building structural components, road
substructures,
cables, pipes, etc.
Heretofore, backhoes have included a first arm pivotally attached to a tractor
and
a second arm pivotally attached to the first arm in a scissors-like manner. A
bucket is
attached to the second arm for digging. Separate hydraulic actuators have
typically been
used to move each of the arms and the bucket. Some of these backhoes have
included an
extendable second arm. Furthermore, some backhoes have included a gripping
device
positioned opposite the bucket for gripping objects between the gripping
device axed the
bucket. One of the gripping devices has included a gripping device statically
attached to
an arm of the backhoe that does not rotate relative to the arm. These gripping
devices
have been difficult to use because the arm and the bucket have to properly
position
relative to the gripping device before the gripping device can be used to pick
up objects.
Another gripping device includes a separate hydraulic actuator for moving only
the
gripping device. These backhoe are expensive to manufacture because of the
cost for
the extra hydraulic actuator and the cost for connecting the gripping device
to the
controls in the tractor. A third gripping device includes thumbs that rotate
simultaneously with the bucket. These backhoes are also difficult to use
because the
bucket and the gripping device must be properly positioned before the gripping
implement can be used. Furthermore, these backhoes are difficult to operate
because the
rotating gripping implement can get in the way of the rotating bucket, thus
makhig the
ground difficult to dig.
SUMMARY OF THE INVENTION
In a digging implement of the present invention, a thumb assembly is
configured
for connection to an extendable linkage having a bucket for holding materials
in the
bucket. The thumb assembly is also configured to rotate as the linkage
extends, wherein
both the bucket and the thumb assembly are independently operable.
-1-

CA 02400917 2002-08-29
WO 02/10522 PCT/US00/20687
These and other features, advantages and objects of the present invention will
be
further understood and appreciated by those skilled in the art by reference to
the
following specification and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a side view of a boom connected to a digging implement in a fully
retracted position of the present invention.
Fig. 2 is side view of the boom connected to the digging implement in a
partially
extending position of the present invention.
Fig. 3 is an exploded side view of a thumb assembly of the present invention.
w
w
Fig. 4 is an exploded top view of the thumb assembly of the present invention.
Fig. 5 is a perspective view of a rod used to connect the thumb assembly to an
extendible linkage of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of description herein, the terms "upper," "lower," "right,"
"left,"
"rear " "front " "vertical " "horizontal " and derivatives thereof shall
relate to the
> > > >
invention as orientated in Fig. 1. However, it is to be understood that the
invention may
assume various alternative orientations, except where expressly specified to
the contrary.
It is also to be understood that the specific devices and processes
illustrated in the
attached drawings, and described in the following specification are simply
exemplary
embodiments of the inventive concepts defined in the appended claims. Hence,
specific
dimensions and other physical characteristics relating to the embodiments
disclosed
herein are not to be considered as limiting, unless the claims expressly state
otherwise.
The reference number 10 (Fig. 1) generally designates a digging implement of
the present invention. The digging implement 10 includes an extendable linkage
12
having a bucket 14 and a thumb assembly 16 for holding materials in the bucket
14. The
thumb assembly 16 is configured to rotate as the linkage 12 extends, and both
the bucket
14 and the thumb assembly 16 are independently operable.
In the illustrated example, the digging implement 10 is pivotally connected at
a
first pivot point 11 to a boom 18 in a scissors-like manner. The boom 18 is
configured
for pivotal attachment to the rear end of a mobile powered tractor (not shown)
for
moving the digging implement 10 to various locations. A combination of the
tractor, the
digging implement 10 and the boom 18 are commonly referred to as a "backhoe."
The
bucket 14 connected to the digging implement 10 can be extended away from the
tractor
_2_

CA 02400917 2002-08-29
WO 02/10522 PCT/US00/20687
by rotating the boom 18 downward relative to the tractor and rotating the
digging
implement 10 upward relative to the boom 18. The digging implement 10 includes
the
extendable linkage 12, which comprising a first telescoping body 20 and a
second
telescoping body 22 in which the second telescoping body 22 can be slid
relative to the
first telescoping body 20 to vary the effective length of the linkage 12 and
thus the reach
of the bucket 14. The illustrated first telescoping body 20 and the second
telescoping
body 22 are a pair of concentric telescoping tubes. Although the first
telescoping body
20 and the second telescoping body 22 are shown as being hollow and
substantially
rectangular, it is contemplated that the first telescoping body 20 and the
second
telescoping body 22 could have any geometric cross-section and the second
telescoping
body 22 could be solid throughout its cross-section. A telescoping hydraulic
actuator
(not shown) within the second telescoping body 22 telescopes the second
telescoping
body 22 outward from the first pivot point 11 within the first telescoping
body 20 in
order to extend the linkage 12.
The illustrated extendable linkage 12 includes the bucket 14 and a telescoping
hydraulic actuator 26 for rotating the bucket 14. The illustrated bucket 14 is
pivotally
attached to an end 28 of the second telescoping body 22 at a second pivot
point 30. An
open mouth 28 of the bucket 14 faces the tractor such that the boom 18 and the
extendable linkage 12 can move the bucket 14 towards the tractor in order to
scoop up
dirt or other objects adjacent the tractor. The telescoping hydraulic actuator
26 is
connected to a pivot sleeve 31 attached to a top surface 32 of the first
telescoping body
20 near the first pivot point 11. The telescoping hydraulic actuator 26 is
also pivotally
connected to a first arm 33 and a second arm 35. The first arm 33 is further
pivotally
connected the second telescoping body 22 between the second pivot point 30 and
the first
telescoping body 20. Likewise, the second arm 35 is further pivotally
connected to the
bucket 14 at a point offset the second pivot point 30. The telescoping
hydraulic actuator
26, the first arm 33 and the second arm 35 are configured to rotate the bucket
14 about
the second pivot point 30 greater than 90° around the end 28 of the
second telescoping
body 22. The telescoping hydraulic actuator 26 can be operated such that the
telescoping hydraulic actuator 26 will extend with the second telescoping body
22 while
the second telescoping body 22 telescopes within the first telescoping body
20.
Therefore, during this operation, the bucket 14 will not rotate relative to
the second
telescoping body 22 as the linkage 12 extends. Likewise, the telescoping
hydraulic
-3-

CA 02400917 2002-08-29
WO 02/10522 PCT/US00/20687
actuator 26 can be operated such that the telescoping hydraulic actuator 26
will extend
while the second telescoping body 22 remains stationary relative to the first
telescoping
body 20. Therefore, during this operation, the bucket 14 will rotate towards
the tractor
and the boom 18. Furthermore, the telescoping hydraulic actuator 26 can be
extended at
. a rate faster or slower than the rate that the second telescoping body 22
telescopes within
the first telescoping body 20 such that the linkage 12 will extend and the
bucket 14 will
rotate relative to the second telescoping body 22.
The illustrated thumb assembly 16 (Figs. 3 and 4) is connected to the
extendable
linkage 12 and includes a thumb 34 rotatably connected to the second
telescoping body
22 and an arm 36 rotatably connected to both the first telescoping body 20 and
the thumb
34. The thumb 34 (Fig. 4) includes a pair of parallel beams 38 being connected
by a
first cross beam 40, a second cross beam 42 and a third cross beam 44. The
beams 38
preferably are slightly curved in the longitudinal direction and include teeth
45 for
grasping objects between the thumb 34 and the bucket 14. The first cross beam
40 has a
substantially U-shaped configuration with a base 46 extending between the
parallel
beams 38 and a pair of legs 48 outside of the parallel beams 38 extending
substantially
parallel to the beams 38. As described in more detail below, the one of the
legs 48 is
bolted or otherwise removably attached to the base 46 of the first cross beam
40 outside
of the parallel beams 38 for allowing the thumb 34 to be easily attached or
removed
from the extendible linkage 12. Bolts 200 are shown as attaching the leg 48 to
the base
46 of the first cross beam 40. A pivot pin 50 is inserted through openings 52
in each of
the legs 48, the bucket 14 and the end 28 of the second telescoping body 22 at
the
second pivot point 30 for connecting the thumb 34 to the second telescoping
body 22.
The thumb 34 and the bucket 14 therefore have a common axis of rotation. The
base 46
of the first cross beam 40 includes a centered notch 54 facing the second
telescoping
body 22 for reception of the second telescoping body 22 as the thumb 34 is
rotated away
from the bucket 14. The second cross beam 42 extends between the beams 38 in a
center portion of the thumb 34 and includes a pair of sleeves 56 for
connection to the
arm 36. The third cross beam 44 extends between the beams 38 at an end of the
beams
38 opposite the first cross beam 40. As described in more detail below, the
third cross
beam 44 is used to grip objects between the bucket 14 and the thumb 34.
The illustrated arm 36 is an elongated shaft with a through hole 58 a first
end and
a pair of sleeves 60 at a second end. The sleeves 60 each include an opening
62 having
-4-

CA 02400917 2002-08-29
WO 02/10522 PCT/US00/20687
a common axis that is parallel to the through hole 58 at the first end of the
arm 36. A
pin 64 (Figs. 1 and 2) is inserted though an opening 65 in a shoulder 66
connected to an
end of the first telescoping body 20 and the through hole 58 of the arm 36 to
pivotally
connect the arm 36 to the first telescoping body 20. A pin 66 (Figs. 1 and 2)
is also
inserted through the sleeves 60 of the arm 36 and an opening 68 in the pair of
sleeves 56
on the second cross beam 42 of the thumb 34 to pivotally connect the arm 36 to
the
thumb 34. The arm 36 forces the thumb 34 to pivot about the second pivot point
30.
In operation, the thumb 34 is pivoted relative to the second telescoping body
22
about the second pivot point 30 by extending the linkage 12. As seen in Fig.
2, the third
cross beam 44 of the thumb 34 is adjacent the bucket 14 when the linkage 12 is
in a fully
retracted position. When the linkage 12 is in the fully retracted position, an
angle
between the thumb 34 and the second telescoping body 22 is at its largest
value. As the
second telescoping body 22 telescopes out of the first telescoping body 20,
the thumb 34
will rotate away from the bucket 14. Since the distance between the second
pivot point
30 and the pin 64 connecting the thumb 34 to the arm 36 and the distance
between the
pin 64 connecting the thumb 34 to the arm 36 and the pin 66 connecting the arm
36 to
the first telescoping body 20 are constant, the angle A between the thumb 34
and the
second telescoping body 22 will get smaller as the second pivot point 30 moves
away
from the pin 66 connecting the arm 36 to the first telescoping body 20.
Therefore, the
arm 36 will force the thumb 34 to rotate away from the second telescoping arm
22.
When the linkage 12 is a fully extended position, third cross beam 44 of the
thumb 34
will be at its farthest position from the bucket 14. Likewise, the arm 36 will
force the
thumb 34 of the thumb assembly 16 towards the bucket 14 as the second
telescoping
body 22 slides into the first telescoping body 20 because the angle 0 between
the thumb
34 and the second telescoping body 22 will get larger as the second pivot
point 30 moves
towards the pin 66 connecting the arm 36 to the first telescoping body 20.
Therefore,
the thumb 34 of the thumb assembly 16 is forced about the second pivot point
30 as the
first 20 and second 22 telescoping bodies telescope.
The illustrated bucket 14 and thumb assembly 16 of the digging implement 10
can be used to grasp objects between the bucket 14 and the thumb 34 of the
thumb
assembly 16 by first creating an opening 100 (as seen in Fig. 1) between the
thumb 34
and the bucket 14 and placing an object within the opening 100. The object can
then be
grasped by the digging implement 10 by either rotating the bucket 14 towards
the thumb
-5-

CA 02400917 2002-08-29
WO 02/10522 PCT/US00/20687
34 or by rotating the thumb 34 towards the bucket 14 by extending the linkage
12. The
object can also be raised or lowered by rotating the linkage 12 relative to
the boom 18
and moved by moving the mobile powered tractor.
An advantage of the illustrated thumb assembly 16 is that the thumb assembly
16
can be retrofitted to operate on a backhoe already having the extendable
linkage 12 and
the bucket 14. First, the shoulder 66 can be welded or otherwise attached to
the first
telescoping body 20. Second, a pin connecting the bucket 14 to the second
telescoping
body 22 could be removed and a new pin 50 could be inserted through the thumb
34, the
bucket 14 and the second telescoping body 22 to replace the old pin. Third,
the arm 36
can be connected to the thumb 34 and the shoulder 66 by inserting the pin 64
though the
opening 65 in the shoulder 66 and the through hole 58 of the arm 36 to
pivotally connect
the arm 36 to the first telescoping body 20. Finally, the pin 66 is inserted
through the
sleeves 60 of the arm 36 and the opening 68 in the pair of sleeves 56 on the
second cross
beam 42 of the thumb 34 to pivotally connect the arm 36 to the thumb 34. It is
noted
that the order of the steps for connecting the thumb assembly 16 to the
linkage 12 can be
rearranged.
Another advantage of the thumb assembly 16 is that the thumb 34 and the arm 36
can be easily attached and removed from the extendible linkage 12. As seen in
Fig. 5,
the pin 50 used to inserted through the thumb 34, the bucket 14 and the second
telescoping body 22 includes a pair of collars 300 on each end of a
cylindrical rod 302 of
the pin 50. The collars 300 each comprise a ring 303 with a radial split 304
from the
inner diameter of the ring 303 to the outer diameter of the ring 303. The
collars also
include a beveled surface 306 with an opening for acceptance of a screw 308 or
other
fastener that extends across the split 304 in the ring 303 of the collar 300.
As the screw
308 is screwed into the opening in the beveled surface 306, the ring 300 will
be
compressed about the split 304 in order to positively connect the collar 300
to the rod
302. Therefore, the pin 50 can be attached to the bucket 14 and the second
telescoping
body 22 by removing one of the collars 300 from one side of the rod 302. The
rod 302
is then extended through the bucket 14 and the second telescoping body 22.
Therefore,
the screws 308 of the collars 300 are loosened and the collars 300 are
centered on the
rod 302 outside of the bucket 14 and the second telescoping body 22.
Consequently, the
rod 302 will have a pair of cylindrical ends extending outside of each of the
collars 300.
Thereafter, the thumb 34 can be easily attached to the pin 50 by first
removing one of
-6-

CA 02400917 2002-08-29
WO 02/10522 PCT/US00/20687
the legs 48 of the first cross beam 40 of the thumb 34. One of the cylindrical
ends of
the rod 302 outside of the collars 300 is then inserted into the opening 52 on
the leg 48
of the first cross beam 40 that is attached to the thumb 34. The other of the
cylindrical
ends of the rod 302 outside of the collars 300 is inserted into the opening 52
on the leg
48 that is removed from the first cross beam 40 of the thumb 34. The removable
leg 48
is then attached to the thumb 34 with the bolts 200 in order to positively
connect the
thumb 34 to the pin 50 and the second telescoping body 22. Moreover, the pin
64
connecting the arm 36 to the first telescoping body 20 and the pin 66 are
common
removable pins that includes a fixed collar on one end and a removable cam
over pin
clip on the other end. Therefore, the pin 64 and the pin 66 can be easily
removed.
Consequently, the arm 36 can be easily removed from the first telescoping body
20 and
the thumb 34. In this manner, only the pin 50 and the shoulder 66 would remain
attached to the linkage 12 when the thumb assembly 16 is removed. The thumb
assembly 16 can therefore be easily attached and removed from the linkage 12
when the
bucket 14 is to be used fox digging only and for other purposed when the thumb
assembly 16 is not required.
The above description is that of the preferred embodiments only. Modifications
of the invention will occur to those skilled in the art and to those who make
or use the
invention. For example, it is contemplated that the extendible linkage 12
could include a
pair of bodies that extend in a manner other than telescoping (e.g., the
bodies of the
extendible linkage could slide relative to one another wherein one of the
bodies is not
located within the other body). Therefore, it is understood that the
embodiment
described above is merely for illustrative purposes and not intended to limit
the scope of
the invention, which is defined by the following claims as interpreted
according to the
principles of patent law, including the Doctrine of Equivalents.

Representative Drawing